I was in a second hand store A couple of months ago and found a kids electronic 130 test lab witch was marked down from 10 bucks to 4 so I bought it to help me learn more about the way electronics work. This has been a very great buy. I finished biulding a O2 and map sensor handling board and took a few trys to get it figured out. I used the board to test my out put on the O2 side and set the map side. It didn't come with any books witch would have been nice but I also have the big electronics for dummys witch helped.
When I got it home I found it also had the smaller one in the box too so I got a bonus pack. The big board take 6 double A's witch will give me 9 volts to test with not a full 12 but makes a good test with out having to go out in this 12 degree weather to test off the car battery and freeze my but off.

Hey Mike thanks. I will see if I can explan it is a duel map and O2 sensor device. I found it while doing a serch for simplest EFIE. I would call it anlog no chip or timmers in it just resistors and 4 trimmer pots.
Voltage come in and is split one leg goes to a 5 volt reg witch is for the map sensor side witch is the one on here or at least the same design. The oter goes to a 10k resistor then to a 1k trimmer and the center of this goes to 10k then to the inlet side of an other 10k trimmer both ground sides of this are hook the the inlet off the O2 sensor side of the SPDT swtch. I have the diagram but it is too big to post on this site. it seams to work on the test board any way.

We have tested the HHO which produce 20 lpm / minute with 500 kva genset and we got 50% fuel efficiency during the test and also the engine was running smooth.Total current was 18 amp which kit was consuming and was producing about 25 LPM.